We want to send SMBs as "atomically" as possible. Prior to sending any data on the socket, cork it to make sure that no non-full frames go out. Afterward, uncork it to make sure all of the data gets pushed out to the wire.
Note that this more or less renders the socket=TCP_NODELAY mount option obsolete. When TCP_CORK and TCP_NODELAY are used on the same socket, TCP_NODELAY is essentially ignored. Signed-off-by: Jeff Layton <[email protected]> --- fs/cifs/connect.c | 4 ++++ fs/cifs/transport.c | 12 ++++++++++++ 2 files changed, 16 insertions(+) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index e8c3e6b..99ca139 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1830,6 +1830,10 @@ cifs_parse_mount_options(const char *mountdata, const char *devname, if (string == NULL) goto out_nomem; + /* + * FIXME: since we now cork/uncork the socket while + * sending, should we deprecate this option? + */ if (strnicmp(string, "TCP_NODELAY", 11) == 0) vol->sockopt_tcp_nodelay = 1; break; diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index 5a1d817..af56e91 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -27,6 +27,7 @@ #include <linux/net.h> #include <linux/delay.h> #include <linux/freezer.h> +#include <linux/tcp.h> #include <asm/uaccess.h> #include <asm/processor.h> #include <linux/mempool.h> @@ -248,12 +249,23 @@ smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst) int n_vec = rqst->rq_nvec; unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base); size_t total_len; + struct socket *ssocket = server->ssocket; + int val = 1; cFYI(1, "Sending smb: smb_len=%u", smb_buf_length); dump_smb(iov[0].iov_base, iov[0].iov_len); + /* cork the socket */ + kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK, + (char *)&val, sizeof(val)); + rc = smb_send_kvec(server, iov, n_vec, &total_len); + /* uncork it */ + val = 0; + kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK, + (char *)&val, sizeof(val)); + if ((total_len > 0) && (total_len != smb_buf_length + 4)) { cFYI(1, "partial send (wanted=%u sent=%zu): terminating " "session", smb_buf_length + 4, total_len); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
